Fix build breakage at 69af2a34f211
Fix build breakage at 69af2a34f211

Fix typo in fx_fnt.h

TBR=dsinclair@chromium.org

Review URL: https://codereview.chromium.org/1777643002 .

DrAlexx/pdfium,DrAlexx/pdfium,DrAlexx/pdfium,DrAlexx/pdfium